THE GEOGRAPHICAL DISTRIBUTION OF MAMMALS 149 



Fig. 55. — Musk Ox (Ovibos wardi) female ; the males have much larger horns 

 — By permission of the N.Y. Zoolog. Soc. 



Fig. 56. — Arctic Fox {Vtilpis lagopus) in winter dress. — By permission of the 

 N.Y. Zoolog. Soc. 



Y 



